Method and means for producing wood veneer

ABSTRACT

The veneer-cutting procedure involves the new step of supporting the workpiece for slicing for forcing a strong backing board to transfer inherent stress to an inherent warp of the workpiece, so that the backing board takes the warp out of the workpiece as the thickness of the workpiece approaches zero value during slicing.

United States Patent Melvin Svviillnger;

Charles F. Hobbs, both 01 Cincinnati. Ohio 15,713

Mar. 2, 1970 Dec. 14, 1971 Polymer Chemicai Company Cincinnati, OhioInventors App]. No. Filed Patented Assignee METHOD AND MEANS FORPRODUCIING WOOD VENEER 25 Claims, 8 Drawing Figs.

Int. Cl B271 5/06 Field of Search 144/327,

[56] References Cited UNITED STATES PATENTS 3,295,571 1/1967 Bork144/327 3,397,723 8/1968 Hervey 144/309 Primary ExaminerDona1d R. SchranAllorney]. Warren Kinney, Jr.

| 18 1,2 '7 l6 1 1 1 11 v 10 W 0x 1 We DEHARKING L I V U L1 22 TPatented Dec. 14, 1971 2 Sheets-Sheet 1 INVENTORS' MELVIN SWILLINGERCHARLES F. HOBBS A T TOR/f Patented Dec. 14, 1971 3,627,006

2 SheetsSheet 2 "1 l r ZZZ]: A EZZZZZ- 60 mama;

INVENTORS MELVIN SWILLINGER CHARLES F. HOBBS MlE'lllllOlD Ahlll) MEANSlFGh lPlltGlDlUCllhlG WGGlD Vllihlllillilit The present inventionrelates to a method and means for producing wood veneer from logs of allkinds.

Several procedures for producing wood veneer are disclosed in the US.Pat. No. 3,295,571, dated Jan. 3, I967 of P. Bork, and reference may behad to said patent for any details of the procedure not necessarilyincluded in the present disclosure. An object of the present inventionis to improve upon the Bork procedures so as to reduce production cost,minimize waste, and increase the yield of veneer from workpieces, or logsections.

In the production of wood veneer, common practice has been to firstsplit a length of log down the middle to produce a half-log, debark andclean it, and plane the surface exposed by splitting so as to provide asubstantially flat and extensive surface having dimensions approximatelythe length and width dimensions of the log section. The section of logso prepared is known in the art as a flitch, and the planedsubstantially flat surface mentioned may properly be referred to as abonding surface by reason of the fact that it will be bonded with acement, glue or other adhesive material to a flat backing board orsupporting layer.

The flitch or workpiece with the backing board or supporting layer gluedthereon is then held in clamps, while a slicing tool or knife repeatedlyshaves veneer leaves from the workpiece, the knife or tool operatingfirst at a distance from the backing board and gradually approaching theplane of the backing board as veneer leaves are successively sliced off.The last leaf removed, therefore, will be very close to and insubstantial parallelism with the mean plane of the backing board. Theknife or slicing tool may operate in a horizontal, vertical, orintermediately inclined plane, depending upon the type of veneer-cuttingmachine employed.

After the workpiece is so consumed, the backing board or supportinglayer is unclamped, removed from the cutting machine, and cleaned ofglue and splinters for reuse.

Usually the glueing of the workpiece to the backing board is preceded bya treatment of the workpiece to improve the appearance and facilitatethe slicing of veneer leaves therefrom. Various forms of treatment havebeen employed, the commonest of which involves moisturizing of theworkpiece for an extended period of time, usually by means of a hotwater bath. After the workpiece has been thoroughly moisturized, theplaned bonding surface thereof may be surface-dried or otherwiseconditioned for glueing to the backing board.

A serious difficulty encountered when applying the backing board, isthat of warping of the bonding surface resulting from the treatmentand/or conditioning aforesaid. The warped bonding surface tends toresist firm attachment of the backing board, and also results in theproduction of objectionably narrow part-leaves as cuts are made closelyapproaching the backing board. Thus, much waste is produced, or slicingmust be terminated before the workpiece is completely used up, and as aresult the most desirable part of the log goes to waste. Moreover, anyinsecure attachment of the backing board to the workpiece may result inaccidents and injuries as the cutter shaves or slices off the veneerleaves with great force.

One of the objects of the present invention is to eliminate insecureattachment of the backing board to the workpiece, and at the same timeincrease the yield of veneer leaves without producing an objectionableamount of waste.

Another object of the invention is to provide an improved method andmeans for producing veneer, which ensures the production of perfectveneer leaves throughout the thickness of the workpiece and very closelyapproaching the line of adhesion between the workpiece and the backingboard.

A further object of the invention is to so secure the workpiece to thebacking board, that the entire veneer-cutting operation may be performedsafely and advantageously with clamping force applied exclusively to theside edges of the backing board, rather than partly to said board and tothe workpiece.

Another object is to utilize the inherent tendency of the backing boardto resume a planar condition after having been flexed and glued to theworkpiece, in advantageously presenting the workpiece to the cutter formaximum production of commercially acceptable veneer leaves from aflitch or workpiece.

The foregoing and other objects are attained by the means describedherein and illustrated upon the accompanying drawings, in which:

FIG. 1 is a diagrammatic view indicating a procedure embodying thepresent invention, for treating or conditioning a log section flitch orworkpiece preparatory to cutting veneer therefrom.

lFllG. 2 is an enlarged perspective view of the flitch or workpiecedisposed for attachment of a backing board.

FIG. 3 is an end elevational view of a press used in adhesive lyattaching the backing board to the workpiece.

lFllG. d is an end view of the workpiece attached to the backing boardby the press of HG. 3.

H6. 5 is a view similar to FIG. l, showing the workpiece arid itsrelationship to the clamp means and cutter of a typical veneer cuttingmachine, and indicating a relationship of elements prevailing at thebeginning of the cutting procedure.

FlG. 6 is a view similar to lFlG. 5 but showing a relationship ofelements prevailing after a number of veneer leaves have been cut fromthe workpiece.

MG. 7 is a view like FlG. t6, showing the relationship of the elementsat an advanced stage at or near termination of the cutting procedure.

lFlG. b is a view similar to FIG. 4 showing a modification.

As FIG. ll discloses, the workpiece W consists of a half-log of anywood, usually up to 15 feet in length, formed by splitting a loglongitudinally down the middle. The exposed under surface where thesplitting occurred, has been planed smooth and flat in a planingmachine.

The half-log so prepared is then advaiiced to a soaking vat 112 orequivalent piece of equipment wherein the half-log, or workpiece, isthoroughly moisturized for the purpose of enhancing the appearance ofthe grain and facilitating slicing in the veneer-cutting machine. Forother methods of conditioning, reference may be made to the Bork patentaforesaid.

Following moisturizing, the workpiece is cleaned in the course ofdebarking at station 114. it is then surface dried, with removal of someof the moisture from flat face ltl, particularly if such surface dryingis conducive to proper adherence of a glue or adhesive thereto. Surfacedrying may be performed in an oven or the like llo, wherein air warmedby heaters lb may be directed onto the flat face lit) by means of one ormore motor driven fans or blowers 20. During the drying period, theworkpiece may be supported upon suitable conveyor rolls 22 whichfacilitate handling of the workpiece.

As before stated, a limited surface drying of face it) may or may not benecessary, depending upon the nature of the adhesive to be appliedthereto. Either before or after the drying period, the workpiece may beplaned to provide a substantially flat face 24 which preferably isparallel to but not as wide as face lift. The planing at face 241 may beperformed by the slicing knife of the veneer cutter, if desired, but itmay be considered better practice to plane at M prior to cutting veneerfrom the workpiece.

After leaving the oven to, the entire face W of the work-- piece iscoated with a glue or adhesive in any suitable manner. In the exampleshown, a spray 26 of glue or adhesive is applied. Then, if the glue oradhesive so requires, heated air may be directed onto the coated surfaceMD in an oven 2% similar to oven to previously described. lFrom oven Ed,the coated workpiece will advance to a press 30, as will be explainedlater.

While the workpiece is undergoing coating as above explained, a coatingof glue or adhesive may be applied to one face 32 of a backing board orsupporting layer 34. Depending upon the nature of the glue or adhesive,the coated backing board or layer may be passed through an oven 36similar to the oven 116. The coating may be applied in any suitablemanner, as by means of a sprayer 38, for example. The backing board 34may be considered similar to the supporting layer 12 of the Bork patentaforesaid.

As suggested by FIG. 2, the backing board is to be superposed upon theworkpiece with the adhesive coated faces 32 and contacting one another.It will be noted that parts 34 and W are of equal length, approximately,and may also be of substantially equal width at faces 10 and 32. Withsaid faces in substantial contact, bonding of the assembly 34, W is tobe completed in a press such as 30 of FIG. 1.

It is important here to note that the aforesaid moisturizing and surfacedrying treatment of workpiece W will usually warp the planed surface 10,thereby to produce a concavity 40 lengthwise of the workpiece (FIG. 3),which precludes effective bonding of the coated surfaces of theworkpiece and the backing board. The backing board, it may be noted, isin the nature of a thick elongate plank or panel which is substantiallyflat, and characterized by limited flexibility and a strong tendency toreturn to planar condition if flexed by external forces. A

One of the features of the present invention involves heavily pressingthe middle portion of the backing board to deliberately distort and flexit transversely, causing said board to bow into firm adhesive contactwith the deep areas of the concave bonding surface 10 of the workpiece.That is, the press force is applied strongly to the backing boardintermediate its side edges 33,33, or along the middle portion thereof.As the adhesive sets under pressure, the result is to adhesivelymaintain the backing board under stress by adhesion to the concavedbonding surface 10 of the workpiece. This condition is exemplified byFIG. 4.

In order to bond the parts as above explained, the press 30 may includea pressure roll or matrix 44 whose working face 46 is convex, or curvedfrom end to end with the diameter of the roll diminishing gradually fromthe midpoint to the opposite ends 48, 48 of the roll. The convexity ofthe roll face should approximate or slightly exceed the complementaryaverage warp concavity of a workpiece surface 10, so that the roll faceunder pressure will flex the backing board into the deepest area of thewarp concavity and effect there a firm bonding of the adhesive coatings,thereby to establish the relationship of FIG. 4, with a virtual absenceof large voids between the parts W, 34. The pressing of the backingboard asabove explained, automatically effects firm bonding of the partslaterally in the direction of the side edges 33 as will be understood.

The press 30 may include a series of conveyor rolls $0, and a supportroll 52 driven by a motor 54. The convex pressure roll or matrix 44 maybe forcefully advanced onto the work by means of hydraulic cylinders 56,56 or equivalent power means as the driven support roll 52 advances theassembly W, 34 toward a receiving conveyor 58. The press, of course, maybe of a type wherein the pressure roll is replaced by a nonrotatingpressure platen or matrix having the required convexity, operatingagainst a flat platen supporting the workpiece. However, the rotary typeof press generally shown is preferred.

After the backing board has been firmly secured to workpiece W, theassembly is advanced to the veneer-cutting machine, which usuallycomprises a table 60 and clamps 62, 62 operable to grip the side edges33,33 of the backing board 34. Inasmuch as the adhesive bond between thebacking board and workpiece W is very secure, it is unnecessary to applythe clamps to workpiece W at any stage of the veneer-cutting operation.That is, the backing board itself provides the necessary clampingsurfaces throughout the veneer cutting operation. The workpieceinitially is supported by the clamps 62 according to FIG. 5, whilecutter 64 reciprocates to slice off successive leaves of veneer from theface 24 of the workpiece.

It will be noted from FIG. 5, that the backing board 34 initially isheld under bending stress by the strong adhesive bond with the concavewarped bonding surface 10 of the workpiece. However, as veneer isprogressively removed from the workpiece by cutter 64 according to FIG.6, the force of the warp in the workpiece gradually weakens and yieldsto the force inherent in the backing board 34 tending to restore thebacking board to planar condition. By reason of the gradual flatteningof the backing board and the workpiece secured thereto, the cutter isenabled to continue slicing off perfect veneer leaves of uniformthickness until substantially the entire workpiece is consumed accordingto FIG. 7.

Under the procedure disclosed by the Bork patent aforesaid, it has neverheretofore been possible to press the backing board or supporting layerinto such intimate contact with the warped bonding surface of theworkpiece, as to achieve the ideal flat relationship and adhesive bonddepicted by the Bork drawing figures. Instead, the workpiece-bondingsurface remained concave, and the backing board remained substantiallyflat, with the result that the bond between them was dangerouslyinsecure, and the cutter in approaching the backing board plane usuallyproduced a divided veneer leaf of reduced commercial value.

The type of veneer-cutting machinery disclosed by the Bork patent, aswell as other known types, can be used in practicing the inventionherein disclosed. Also, there need be no difference in the nature of thebacking boards or supporting layers employed, nor in the nature of theglue or adhesive so long as a strong bond is obtainable. Onesatisfactory form of adhesive comprises a synthetic rubber-resincombination which is dissolved in a volatile solvent. Such glue shouldhave enough inherent strength to withstand the shearing stressesencountered in the veneer cutting machine, so that the workpiece safelyis held to the backing board while undergoing cutting, withoutinterruption, all the way to the glue line.

The backing board may be of wood or any composition of material havingthe qualities above mentioned. It should be of such nature as to acceptand strongly adhere to the glue or adhesive. The board may be wider thanthe workpiece as in FIG. 4, or slightly narrower as in FIG. 8, andshould have a thickness between 1 and 2 inches. Also,'the board shouldbe soft enough to avoid injuring the veneer slicing blade if struckthereby, and hard enough to withstand the clamping force imposed by theveneer-cutting machine clamps.

For other details not necessarily pertinent to the present invention,reference may be had to the Bork patent hereinbefore identified.

We claim:

I. The method of producing a succession of veneer leaves by repeatedlysubjecting a log section workpiece to substantially parallel cuts of aslicing tool, said method comprising the steps of: establishing upon theworkpiece an initially substantially flat and extensive bonding surface;subjecting the workpiece to a treatment which facilitates slicing butwarps said bonding surface to produce concavity thereof; superimposingupon the concave bonding surface a substantially flat elongate backingboard, with an adhesive material therebetween, said backing board beingof limited flexibility and characterized by a strong tendency to returnto planar condition after flexing; subjecting the workpiece and thesuperimposed backing board to the compressive action of a highlypressured matrix which applies to the backing board between its sideedges a heavy force sufficient to flex said backing board into firmadhesive contact with the deep areas of said bonding surface concavity,thereby to adhesively maintain the backing board under stress byadhesion to said concaved bonding surface; then removing the matrixpressure; then while said backing board is under stress by adhesionalone, slicing veneer leaves successively from the workpiece insubstantial parallelism with the mean plane of the backing board untilthe warping force in the workpiece is gradually weakened by the removalof workpiece material, and until said warping force is substantiallyovercome by the force inherent in the backing board acting to restorethe backing board and the adherent bonding surface of the workpiece toinitial substantially flat condition, said slicing continuing into closeproximity to said backing board.

2. The method as defined by claim 1, which includes holding theworkpiece while undergoing slicing, by clamping the adhesively attachedbacking board to a support.

3. The method as defined by claim 1, wherein said treatment tofacilitate slicing includes moisturizing the workpiece.

4. The method as defined by claim 3, which includes the step of removingsome of the moisture from the bonding surface of the workpiece prior toapplying the adhesive.

5. The method as defined by claim ll, wherein said backing board isflexed into firm adhesive contact with said bonding surface by rolling.

6. The method as defined by claim 4, which includes holding theworkpiece while undergoing slicing, by clamping the adhesively attachedbacking board to a support.

7. The method as defined by claim 6, wherein the clamping is effected atthe side edges of the backing board throughout the veneer-cuttingoperation.

8. The method of preparing for veneer cutting a loglike workpiece whichhas a bonding surface planed and subsequently warped to concavity, saidmethod comprising: su-

perposing upon said bonding surface a flat elongate backing board withan adhesive between said board and said bonding surface; said backingboard being of limited flexibility and characterized by a strongtendency to return to planar condition after flexing; then subjectingthe workpiece and the superposed backing board to the compressive actionof a highly pressured matrix which applies to the backing board betweenits side edges a heavy force sufficient to flex said backing board intofirm adhesive contact with the deep areas of said bonding surfaceconcavity, thereby to adhesively maintain the backing board under stressby adhesion to said concaved bonding surface.

9. The method as defined by claim 8, wherein the matrix is in the formof an elongate member having a convex pressure face substantiallycomplementary to the surface concavity of the workpiece.

10. The method as defined by claim 9, wherein said elongate member is apressure roll whose diametral dimension diminishes gradually from themidpoint of the pressure face toward the opposite ends of the. roll.

11. The method as defined by claim it], wherein the backing board has awidth dimension approximating the width dimension of the workpiece.

12. The method as defined by claim 8, wherein the backing board has awidth dimension approximating the width dimension of the workpiece.

13. The method as defined by claim 8, which includes the steps ofclamping said backing board in a veneer-cutting machine, and slicingveneer leaves successively from the workpiece to diminish the thicknessof the workpiece, thereby to weaken the force of the warp thereof andenable the strong tendency of the backing board to return to planarcondition, to substantially overcome the warp of the workpiece duringthe slicing operation.

14. The method as defined by claim 13, wherein the matrix is in the formof an elongate member having a convex pressure face substantiallycomplementary to the surface concavity of the workpiece.

15. The method as defined by claim 14, wherein said elongate member is apressure roll whose diametral dimension diminishes gradually from themidpoint of the pressure face toward the opposite ends of the roll.

16. The method as defined by claim 15, wherein the backing board has awidth dimension approximating the width dimension of the workpiece.

R7. The method as defined by claim 8, wherein said adhesive constitutesone coating applied to the warped bonding surface of the workpiece, andanother coating applied to one face of the backing board.

18. The method as defined by claim 17, which includes the steps ofclamping said backing board in a veneer-cutting machine, and slicingveneer leaves successively from the workpiece to diminish the thicknessof the work iece, thereby to weaken the force of the warp thereof andena le the strong tendency of the backing board to return to planarcondition, to substantially overcome the warp of the workpiece duringthe slicing operation.

19. The method as defined by claim 18, wherein the matrix is in the formof an elongate member having a convex face substantially complementaryto the surface concavity of the workpiece.

20. The method as defined by claim 19, wherein said elongate member is apressure roll whose diametral dimension diminishes from the midpoint ofthe pressure face toward the opposite ends of the roll.

21. The method as defined by claim 19, wherein the backing board has awidth dimension approximating the width dimension of the workpiece.

22. Mechanism for producing veneer from an elongate loglike workpiecehaving an initially substantially flat and extensive bonding surface,said means comprising in combination; means for subjecting the workpieceto moisture sufficient to warp said bonding surface and impart concavitythereto; an elongate substantially flat backing board of limitedflexibility and characterized by a strong tendency thereof to return toplanar condition after flexing; means for pressing said board onto theconcave bonding surface of said workpiece with an adhesive interposed,said means comprising an elongate pressure member having a convexpressure face substantially complementary to the surface concavity ofthe workpiece, said pressure member applying heavy force mainly to thatarea of the backing board which is intermediate the side edges of saidboard, thereby to flex said backing board into firm adhesive contactwith the deep areas of said bonding surface concavity to maintain thebacking board under stress by adhesion to said concaved bonding surface;clamp means operative upon termination of the pressing operation, togrip the backing board; and means including a cutter for successivelyslicing veneer leaves from the workpiece while held. by the clamp meansand maintained under stress by the adherent stressed backing board, theslicing being performed in planes substantially parallel to the meanplane of the backing board.

23. The combination as defined by claim 22, wherein the combinationincludes means for surface drying the bonding surface of the moisturizedworkpiece, and for applying adhesive to said dried surface.

24. The combination as defined by claim 22, wherein the backing boardhas a width dimension approximating the width dimension of theworkpiece.

25. The combination as defined by claim 22, wherein said elongate memberis a rotary pressure roll for applying force upon said backing board;and means for progressively advancing the workpiece relative to saidpressure roll.

lOlOlA man

1. The method of producing a succession of veneer leaves by repeatedlysubjecting a log section workpiece to substantially parallel cuts of aslicing tool, said methoD comprising the steps of: establishing upon theworkpiece an initially substantially flat and extensive bonding surface;subjecting the workpiece to a treatment which facilitates slicing butwarps said bonding surface to produce concavity thereof; superimposingupon the concave bonding surface a substantially flat elongate backingboard, with an adhesive material therebetween, said backing board beingof limited flexibility and characterized by a strong tendency to returnto planar condition after flexing; subjecting the workpiece and thesuperimposed backing board to the compressive action of a highlypressured matrix which applies to the backing board between its sideedges a heavy force sufficient to flex said backing board into firmadhesive contact with the deep areas of said bonding surface concavity,thereby to adhesively maintain the backing board under stress byadhesion to said concaved bonding surface; then removing the matrixpressure; then while said backing board is under stress by adhesionalone, slicing veneer leaves successively from the workpiece insubstantial parallelism with the mean plane of the backing board untilthe warping force in the workpiece is gradually weakened by the removalof workpiece material, and until said warping force is substantiallyovercome by the force inherent in the backing board acting to restorethe backing board and the adherent bonding surface of the workpiece toinitial substantially flat condition, said slicing continuing into closeproximity to said backing board.
 2. The method as defined by claim 1,which includes holding the workpiece while undergoing slicing, byclamping the adhesively attached backing board to a support.
 3. Themethod as defined by claim 1, wherein said treatment to facilitateslicing includes moisturizing the workpiece.
 4. The method as defined byclaim 3, which includes the step of removing some of the moisture fromthe bonding surface of the workpiece prior to applying the adhesive. 5.The method as defined by claim 1, wherein said backing board is flexedinto firm adhesive contact with said bonding surface by rolling.
 6. Themethod as defined by claim 4, which includes holding the workpiece whileundergoing slicing, by clamping the adhesively attached backing board toa support.
 7. The method as defined by claim 6, wherein the clamping iseffected at the side edges of the backing board throughout theveneer-cutting operation.
 8. The method of preparing for veneer cuttinga loglike workpiece which has a bonding surface planed and subsequentlywarped to concavity, said method comprising: superposing upon saidbonding surface a flat elongate backing board with an adhesive betweensaid board and said bonding surface; said backing board being of limitedflexibility and characterized by a strong tendency to return to planarcondition after flexing; then subjecting the workpiece and thesuperposed backing board to the compressive action of a highly pressuredmatrix which applies to the backing board between its side edges a heavyforce sufficient to flex said backing board into firm adhesive contactwith the deep areas of said bonding surface concavity, thereby toadhesively maintain the backing board under stress by adhesion to saidconcaved bonding surface.
 9. The method as defined by claim 8, whereinthe matrix is in the form of an elongate member having a convex pressureface substantially complementary to the surface concavity of theworkpiece.
 10. The method as defined by claim 9, wherein said elongatemember is a pressure roll whose diametral dimension diminishes graduallyfrom the midpoint of the pressure face toward the opposite ends of theroll.
 11. The method as defined by claim 10, wherein the backing boardhas a width dimension approximating the width dimension of theworkpiece.
 12. The method as defined by claim 8, wherein the backingboard has a width dimension approximating the width dimension of theworkpiece.
 13. The method as defined by claim 8, which inclUdes thesteps of clamping said backing board in a veneer-cutting machine, andslicing veneer leaves successively from the workpiece to diminish thethickness of the workpiece, thereby to weaken the force of the warpthereof and enable the strong tendency of the backing board to return toplanar condition, to substantially overcome the warp of the workpieceduring the slicing operation.
 14. The method as defined by claim 13,wherein the matrix is in the form of an elongate member having a convexpressure face substantially complementary to the surface concavity ofthe workpiece.
 15. The method as defined by claim 14, wherein saidelongate member is a pressure roll whose diametral dimension diminishesgradually from the midpoint of the pressure face toward the oppositeends of the roll.
 16. The method as defined by claim 15, wherein thebacking board has a width dimension approximating the width dimension ofthe workpiece.
 17. The method as defined by claim 8, wherein saidadhesive constitutes one coating applied to the warped bonding surfaceof the workpiece, and another coating applied to one face of the backingboard.
 18. The method as defined by claim 17, which includes the stepsof clamping said backing board in a veneer-cutting machine, and slicingveneer leaves successively from the workpiece to diminish the thicknessof the workpiece, thereby to weaken the force of the warp thereof andenable the strong tendency of the backing board to return to planarcondition, to substantially overcome the warp of the workpiece duringthe slicing operation.
 19. The method as defined by claim 18, whereinthe matrix is in the form of an elongate member having a convex facesubstantially complementary to the surface concavity of the workpiece.20. The method as defined by claim 19, wherein said elongate member is apressure roll whose diametral dimension diminishes from the midpoint ofthe pressure face toward the opposite ends of the roll.
 21. The methodas defined by claim 19, wherein the backing board has a width dimensionapproximating the width dimension of the workpiece.
 22. Mechanism forproducing veneer from an elongate loglike workpiece having an initiallysubstantially flat and extensive bonding surface, said means comprisingin combination; means for subjecting the workpiece to moisturesufficient to warp said bonding surface and impart concavity thereto; anelongate substantially flat backing board of limited flexibility andcharacterized by a strong tendency thereof to return to planar conditionafter flexing; means for pressing said board onto the concave bondingsurface of said workpiece with an adhesive interposed, said meanscomprising an elongate pressure member having a convex pressure facesubstantially complementary to the surface concavity of the workpiece,said pressure member applying heavy force mainly to that area of thebacking board which is intermediate the side edges of said board,thereby to flex said backing board into firm adhesive contact with thedeep areas of said bonding surface concavity to maintain the backingboard under stress by adhesion to said concaved bonding surface; clampmeans operative upon termination of the pressing operation, to grip thebacking board; and means including a cutter for successively slicingveneer leaves from the workpiece while held by the clamp means andmaintained under stress by the adherent stressed backing board, theslicing being performed in planes substantially parallel to the meanplane of the backing board.
 23. The combination as defined by claim 22,wherein the combination includes means for surface drying the bondingsurface of the moisturized workpiece, and for applying adhesive to saiddried surface.
 24. The combination as defined by claim 22, wherein thebacking board has a width dimension approximating the width dimension ofthe workpiece.
 25. The combination as defined by claim 22, wherein saidelongate member is a rotary pressure roll for applying force upon saidbacking Board; and means for progressively advancing the workpiecerelative to said pressure roll.